Rotary drum fluid/liquid separator with energy recovery means

ABSTRACT

A rotating drum divided in axial spaced compartments with one of the compartments includes paddles and coalescing material to separate the fluid from the liquid and the other compartment includes stationary oil pumping and water pumping means and an energy recovery means for effectively separating fluid such as oil from liquid such a water. Another embodiment includes a simplified version of the fluid/liquid separator adapted for zero gravity environment and includes means for purging the lines from air prior to pumping the liquid. An electrical sensing circuit including conductivity sensors or an electronic controller including pressure sensors serve to control the rate of removal of the separated component or controlling said purging means.

TECHNICAL FIELD

This invention relates to a fluid separator that can separate mixtureswhose components are of different densities and more specifically forseparating the components of oil and water or air and water mixtures.

BACKGROUND ART

It is well known that there is a need for a practical oil/waterseparator that can cleanse oil spills that occur in bodies of water,such as the oceans, rivers, lakes, and streams. While there aredifferent fluid separation techniques, all of these have drawbacks whichrender them inadequate to meet present day needs.

One such system, for example, is exemplified in U.S. Pat. No. 3,742,095granted to Mensing et al on Jul. 3, 1973 entitled "Vortex Flow Systemfor Separating Oil from an Oil-Water Mixture and commonly assigned toUnited Technologies Corporation, is a system and apparatus that wasintended to cleanse the seas by employing an improved vortex separator.Other systems have been contemplated that centrifuge the fluid in arotating drum causing the denser liquid to centrifuge to gravitate tothe periphery of the rotating drum where it can be collected by astationary pitot tube immersed in the fluid. The pitot tube, however,creates fluid turbulence which limits the water purity attainable withthis concept. This turbulence also increases power consumption, acritical consideration in space-based applications where available poweris limited.

Other separation techniques do not rely on centrifugation of the fluidmixture to achieve separation. One such method includes burning the oilonce it has been contained. Typically, containment is by use of floatingbooms that are positioned into place by the use of a vessel. Problemswith this approach are that the oil is not recovered, air pollution isgenerated by the burning process, and the oil is not completely consumedby the burning, hence, the cleanup is incomplete.

Another method utilizes skimmers which pick up oil along with the waterfrom the water surface. The skimming may be by vacuum pumps which pumpthe oil/water mixture in to a compartment in the hull of a ship. Anotherapproach would be to force the mixture into a compartment by the use ofbelt skimmer. In either case, the primary mechanism for separation isgravity, i.e. oil which is less dense than water rises to the top of thecompartment. Obviously, in addition to the fact that this process isslow, it also has the disadvantage that it requires many more trips tocarry the oil/water mixture to off shore containers where the oil isallowed to settle at the top, than it would otherwise require ifcomplete separation were achieved at sea. This is so because if completeseparation were achieved at sea, the water could be pumped overboard andthe entire compartment would be available for oil storage. Furthermore,separation efficiency by gravity is not nearly as good as withcentrifugal separation, since with the latter, several thousand timesthe gravitational acceleration can be achieved by the rotation of thefluid mixture.

I have found that I can obviate the problems enumerated in the aboveparagraphs and in accordance with this invention I provide a practicaland efficacious centrifugal fluid separator that can be utilized toclean up marine oil spills. It is contemplated that this invention canbe utilized to separate the components of any fluid mixture when thecomponents are of different densities.

As one skilled in this art will appreciate the concept of this inventionis particularly suited for separating oil from an oil/water mixturehowever, it affords a multitude of applications for fluid componentseparation and hence it is not limited in use for oil/water separation.For example, as will become evident from the description to follow, thesame basic concept, with some minor modifications, could be used forseparation of gas from liquid/gas mixtures, which is a critical processin spacecraft life support systems. Likewise, depending on whether highoutput flow or high pressure rise is desired slightly differentconfiguration of certain components may be utilized to meet these needs.It will become readily apparent that the description of the preferredembodiment of the water/oil separator will provide a basis forunderstanding how the invention can be applied for use in otherenvironments, since the same basic principles of operation apply in allcases.

SUMMARY OF THE INVENTION

An object of this invention is to provide an improved fluid separator.

According to this invention and when used to separate oil from anoil/water mixture, a rotating drum centrifugally separates the oil andwater and the heavier water is forced to the periphery of the drum.Circular disk pumping assemblies are used to collect the separatedfluids and transport them out of the separator. The rotating drumconsists of two compartments. In the upstream compartment, oil and waterare separated and oil is pumped out of the rotating drum. In thedownstream compartment water is pumped out of the assembly. An energyrecovery disk located between the two compartments serves to transportthe water flow exiting the upstream compartment from the periphery ofthe rotating drum where it enters the downstream compartment and thenpumped to the separator outlet.

A feature of this invention is the use of a conductivity sensor tocontrol the level of the oil/water interface in the upstream compartmentof the drum.

Another feature of this invention is the provision of several layers ofcoalescing mesh in the upstream compartment of the rotating drum. Themesh serves to help the oil coalesce and thus aids the separationprocess.

Another feature of this invention is the use of impeller blades embeddedin the coalescer mesh that accelerates the incoming fluid mixture.

The improved fluid separator is characterized as being relatively lightin weight, compact in size, and capable of removing virtually all of theoil from the water at substantially high rates with a considerableavoidance of high power consumption as would be necessary in heretoforeknown water separators utilizing pitot tubes to collect and transportthe separated fluids. The purity of the oil can readily be controlled bycontrolling the residence time in the separator and the rotational speedof the drum.

This invention includes certain features which are deemed unique influid separators and because of the uniqueness afford certain benefitswhich, without intending to limit the scope of this invention, arelisted hereinbelow:

1) The circular disk pumping assemblies of this invention collect theseparated fluids and transport them out of the separator while avoidingturbulence and thereby reducing power consumption.

2) The utilization of the two compartments in the rotating drum isolatesthe water pumping function from the oil/water interface in the upstreamcompartment resulting in greater purity of water output.

3) The energy recovery disk directs water from the periphery of therotating drum radially inward to the water pump inlet while preventingthe energy losses due to fluid shear which would occur if the energyrecovery disk were not present.

4) The conductivity sensors control the level of the oil/water interfacein the upstream compartment, thus assuring that the water removed fromthe separator is not contaminated with oil.

5) The layers of mesh coalesce the fluids to improve the oil/waterseparation performance and the embedded impeller blades reduceturbulence during the acceleration of the fluid.

The foregoing and other features of the present invention will becomemore apparent from the following description and accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cut away perspective view in elevation of the oil/waterconfiguration of the fluid separator illustrating the details of thisinvention;

FIG. 2 is a sectional and schematic representation of the embodimentdepicted in FIG. 1;

FIG. 3 is a sectional view and schematic representation of a liquid gasseparator capable in a zero gravity atmosphere;

FIG. 3A is a sectional view taken through the lines 3A--3A of FIG. 3;

FIG. 4 is a cross sectional view and schematic representationexemplifying another embodiment of the type of separator depicted inFIG. 3;

FIG. 5 is a sectional view in elevation and schematic illustratinganother embodiment of the type of separator depicted in FIG. 3; and

FIG. 6 is a sectional view in elevation and schematic exemplifyinganother embodiment of this invention utilizing a positive displacementpump for minimizing power consumption.

BEST MODE FOR CARRYING OUT THE INVENTION

While the preferred embodiment of this invention is being described as awater/oil separator for cleansing oil spills in the seas, as one skilledin this art will appreciate, this invention has utility for otherapplications and can operate to separate other media. Additionally withminor modifications this invention can be adapted to operate in a zerogravity or partial gravity environment for separating a gaseous andliquid mixture.

As best seen in FIGS. 1 and 2, the fluid separator for separating thecomponents of an oil/water mixture is generally indicated by referencenumeral 10 as comprising rotating major components and stationary majorcomponents listed hereinbelow for the sake of convenience and forsimplifying the description of this invention:

(It being understood that the embodiment depicted in FIGS. 1 & 2exemplify the basic principles of all the embodiments described herein).

    ______________________________________                                        ref. no.       component                                                      ______________________________________                                        ROTATING COMPONENTS:                                                          12             rotating drum                                                  14             impeller vanes                                                 16             coalescer                                                      18             conductivity electrodes                                        20             Oil pump housing                                               22             rotating drum divider                                          24             water pump housing                                             26             energy recovery disk                                           28/30          bearings                                                       32             slip rings                                                     34             water pump housing bolts                                       36             outlet tube assembly                                           38             outlet tube assembly bolts                                     40             pulley wheels (belt drive)                                     STATIONARY COMPONENTS:                                                        42             stationary inlet                                               44             disk pump assembly                                              44a           oil pump disk                                                   44b           water pump disk                                                ______________________________________                                    

The disk pump assembly 44 consists of the oil pump disk 44a and thewater pump-disk 44b where the oil pump disk 44a fits inside the oil pumpcavity 46 of the rotating drum 12 and the water pump disk 44b fitsinside the water pump cavity 48.

The rotating drum 12 is generally cylindrical in shape and converges ina frustoconically shaped forward end defining a circular opened end andis supported between the suitable bearings 28 and 30 for rotary movementabout the central axis A. The diameter of stationary sleeve 50 which isdisposed concentrically and coaxially at the opened end is smaller thanthe diameter of the opened end and defines an outer annular passage 52for venting air and an inner passage for defining the inlet 54.

The rotating drum essentially is divided into two distinct compartments,48a and 48b. Compartment 48a is located at the fore end of the separatoradjacent to the inlet and extends between the inlet and up to andincluding the oil pump housing 20 and compartment 48b extends in the aftdirection from the oil pump housing 20 to the outlet of the separator.As will be appreciated by the description to follow, by isolating thewater pumping function from the oil/water interface, a greater purity ofthe water output is attainable. This also lends itself to incorporatingthe energy recovery disk 26 which is mounted between the rotating drumdivider 22 and the water pump housing 24 and which enables powerconsumption to be reduced.

The oil/water mixture enters the rotating drum 12 through the inlet 54and immediately impinges the circumferentially spaced impeller vanes 14which extend radially inward from the inner diameter of the rotatingdrum 12 toward the axis A. While the number of vanes are dependent onthe particular application, in the preferred embodiment the number ofvanes are eight (8). The vanes are contoured such that upon impingement,the mixture is rapidly accelerated to the rotational speed of therotating drum 12. The forces due to centripetal acceleration of themixture cause the components to separate. Since the water is the denseri.e. heavier fluid, it will be driven to the periphery of rotating drum12 and form into a cylindrical mass conforming to the shape of the innersurface of rotating drum 12. The oil which is the less dense fluid, i.e.lighter, will be driven closer to axis A and forms on the inner diameterof the water mass a cylindrical mass concentric and contiguous to themass of water and rotates therewith at the same rotational speed. Adistinct interface of the oil/water will form as represented by thedashed line B. Since the forces due to centripetal acceleration may bemany thousand times the force of gravity, the separation by the rotatingdrum occurs very rapidly and efficiently.

To more effectively perform the separation process a suitable coalescer16 may be utilized. Coalescer 16 is comprised of porous filter mesh thatis in sheet form and either helically wound or formed in layers andextends in the rotating drum 12 from the forward to the rearward end.The coalescing filter mesh provides surface area on which the oildroplets coalesce into larger droplets thusly, enhancing separation.

The level of the separated oil in the rotating drum 12 is determined bythe diameter of the entrance 56 to the oil pump housing 20. Since thisdiameter is slightly larger than the inside diameter of the inlet 54 ofthe rotating drum 12 there is a clearance between the surface of theseparated oil and the outside diameter of the sleeve 50 of stationaryinlet 42. Any air trapped in the oil/water mixture will escape toambient through the annular passage 52.

As the separated oil and water flow axially toward the outlet end ofrotating drum 12, the continued action of centripetal accelerationforces serves to increase the purity of the outlet oil and water. Oncethe level of the separated oil exceeds the level of the entrance 6 ofthe oil pump housing 20, the separated oil flows into the oil pumphousing 20 where it is again flung to the periphery of the pump cavity46. A plurality of circumferentially spaced radial vanes 59 in the oilpump cavity 46 ensure that the rotational velocity of the oil ismaintained. As the oil level in oil pump cavity 46 rises above theperiphery of the stationary oil pump disk 44a in the disk pump assembly44, it impinges on the plurality of circumferentially spaced vanes 58disposed in the oil pump disk 44a. The vanes 58 redirect the oil flowradially inward and pump it to the central passageway 60 extending intothe outlet tube assembly 36 to flow axially out of the separator to becollected.

Separated water at the periphery of the rotating drum 12 at the aft end(i.e. left in FIGS. 1 and 2) of compartment 48a flows axially throughcircumferentially spaced passages 62 formed in the periphery of oil pumphousing 20 and the circumferentially spaced passages 64 formed in therotating drum divider 22. Flow of the water then continues radiallyinward through passages 66 formed in the energy recovery disk 26. Thefunction of the energy recovery disk 26, which is clamped between therotating drum divider 22 and the water pump housing 24, is to reducefrictional energy losses due to vortex flow which would occur if thismechanism weren't provided. After flowing radially inward to the insidediameter of the energy recovery disk 26, the water flows axially back tothe water pump cavity 48 where it is flung to the outer periphery of thewalls defining this cavity.

Operation of the water pump is essentially the same as the operation theoil pump. Namely, the circumferentially spaced radial vanes 70 formed inthe periphery of the water pump housing 24 maintain the rotationalvelocity of the water. As the water level in water pump housing risespast the periphery of the stationary water pump disk 44b of the diskassembly 44, the circumferentially spaced vanes 72 in the water pumpdisk 44b redirect the water radially inward and pump it to the wateroutlet through annular passage 74 between the outlet tube of the oilpump disk 44a and the outlet tube of the water pump disk 44b. Because ofthe lower viscosity of the water, the stationary water disk pump 44b canhave a narrower cross section than that of the stationary oil disk pump44a.

Conductivity sensors 18 are utilized to ensure that the oil does notcontaminate the water outlet. In the preferred embodiment theconductivity sensor includes a pair of suitable metal electrodes 18mounted a fixed distance apart on the upstream side of the oil pumphousing 20 such that they are immersed in the fluid. This controlconcept utilizes the fact that oil and water have significantlydifferent electrical conductivities. The electrodes are connected to oneleg of a suitable bridge electrical circuit whose output is sensitive tochanges in conductivity detected by the electrodes 76. The bridgecircuit resistances are selected such that there is no voltage outputfrom the bridge circuit 78 when the electrodes 18 are immersed in water.If the oil/water interface, i.e. line B migrates too far toward theperiphery of the rotating drum 12, the electrodes will become immersedin oil, and the resulting change in conductivity sensed by electrodes 18cause the bridge circuit to produce an output signal. This signal whichis in millivolts causes a suitable relay or controller 82 to close asuitable solenoid valve 82 to shut down the flow of water connected tothe water outlet of outlet tube assembly 36. With the water outletclosed, the oil/water mixture continuing to flow into the stationaryinlet 42, and oil continuing to be pumped out of the oil outlet, theoil/water interface migrates away from the periphery of rotating drum 12and places the electrodes into contact with the separated water again tonull out the system. This causes the bridge circuit output to return tozero and triggering automatic opening of the solenoid valve to resumeflow of the water.

There are several other approaches utilizing conductivity sensors toensure purity of the output water that may be employed with thisinventive separator concept. As for example, conductivity sensorslocated close to the inlet of the oil pump housing 20 may be used tocontrol a valve in the oil outlet line. In this case, when the oil/waterinterface approaches too close to the inlet of the oil pump housing, thechange in sensed conductivity may be used to close a valve in the oiloutlet line and/or open a valve in the water outlet line until theoil/water interface recedes from the vicinity of the oil pump inlet.

Another approach for a conductivity sensor would be a dual level controlwhich may be achieved by placing two sets of conductivity sensors on theupstream side of oil pump housing 20, one near the periphery of therotating drum 12 and the other near the inlet 56 of the oil pump housing20. In this case, the sensor near the periphery might trigger therestriction of the water outlet flow when the oil/water interfaceapproached the periphery of the rotating drum 12 and the release of thatrestriction as the oil/water interface receded from the periphery.Likewise, the sensor located near the outlet flow when the oil/waterapproached the pump inlet,and the release of that restriction as theoil/water interface receded from the pump inlet.

And still another approach for conductivity sensing is utilizing aproportional control consisting of two parallel metal electrodesoriented radially along the upstream face of the oil pump housing 20.These electrodes would be part of a bridge circuit as described in theparagraphs above. The output of the bridge circuit would vary linearlywith the position of the oil/water interface. This voltage output wouldproportionately vary the restrictions in the water and oil outlet linesin order to maintain an oil/water interface level in the rotating drum12 consistent with the relative flow rates of oil and water entering theseparator 10.

Passages in the water/oil separators are sufficiently large in order toaccommodate debris and foreign matter. The disk pumps are designed toprovide a grinding or macerating capability in order to reduce the sizeof any debris.

These systems depicted in FIGS. 1 and 2 will typically be mounted on aship (although other environments are contemplated within the scope ofthis invention) and receive oil and seawater in from floating orship-mounted oil skimming devices. The separators serve as oilconcentrators by taking the skimmer output (contemplated as being 80%water) and concentrating the oil to better than 99% purity and returningsubstantially greater than 99% (or better) oil free water to the sea.This obviously affords a significant advantage. Since water is separatedfrom oil at sea the skimmer collection vessel can collect up to fivetimes as much oil before returning to port and off loading.

In addition to water/oil separation at sea, this invention isparticularly useful for shoreline remediation by picking up oil near theshore as it is manually dislodged by high pressure water spray. Further,this invention would have utility in industrial applications where itcould be applied in removing oil or other pollutants from watereffluent, sumps or ponds. Such separators when utilized in a wastewateroutlet could be continuously online so as to protect against aninadvertent spill and provide a warning of oil present in the industrialoutput.

As one skilled in this art will appreciate the fluid separator 10 can beutilized for a sundry of applications as, for example, removing waterfrom diesel oil, or to clean up shipboard bilges, or to removeimpurities from industrial process flows. This invention is particularlyefficacious for these applications because it affords advantages ofcompact size, rapid separation, i.e. high throughput, and high purityoutput.

Additionally, this invention can be reconfigured for applications inzero or partial gravity environments, such as those encountered inspacecraft. Obviously, the absence of gravity makes the separation ofliquids from process gas flows difficult. This invention sufficientlyreconfigured as will be described hereinbelow, affords advantages in anumber of different applications, as for example, the separation of heatexchanger humidity condensate from process air flow, and the separationof urine from waste collector system air flow, i.e. commodes.

While centrifugal separators are currently used in many applications inspacecraft, all of these separators use pitot tubes to collect theseparated liquid. The use of pitot tubes causes much turbulence in theseparated liquid, which results in high power consumption, which is adistinct disadvantage in spacecraft, and problems with gas inclusion inthe output liquid. The disk pump feature of my fluid separator willgreatly reduce power consumption and virtually eliminate the gasinclusion problem.

The liquid/gas separator of this invention is schematically depicted inFIG. 3 and like the oil/water separator a rotating drum generallydesignated by reference numeral 100 is rotatably mounted about therotating axis C. As mentioned in the above paragraphs, thisconfiguration illustrates the basic design that can be employed in aspacecraft life support system to separate the condensing heat exchangerhumidity condensate water from process air flow prior to returning theair to the spacecraft cabin. In the microgravity environment of space,the water condensed in the heat exchanger would be entrained in theprocess air flow and carried to the separator inlet.

The rotating bowl 100 consists of a cylindrical housing 102 flaringoutwardly at its aft end and containing a plurality of circumferentiallyspaced separator impellers 116 extending radially inward toward axis Cadjacent to the centrally disposed inlet 112. The fan impellers 104 inthe aft end of the rotating bowl 100 draw the air and entrained waterdroplets into the inlet 112. The separator impellers 116, located justinside the inlet impart a rotational velocity to the air and theentrained water droplets. As with the oil/water separator depicted inFIGS. 1 and 2, the heavier water is centrifuged to the periphery of therotating bowl 100. The lighter air remains in the center of the rotatingbowl 102 and is accelerated out the air outlet 114 by the fan impellers104. The air is admitted to the fan impellers via a plurality ofcircumferentially spaced air inlets 126. Fan impellers arecircumferentially mounted in the larger diameter aft portion of the bowl100 and extend radially outward from the outlets of the air passages 126to the air outlet 114. The bowl 100 is cantilever mounted to shaft 110which is rotatably driven by a suitable motor (not shown).

A stationary disk pickup and pump 120 and elongated liquid outlet tube122 are mounted to an external assembly (not shown) and fixed centrallyinside of bowl 100. The disk pickup and pump 120 serves to collect thewater flung to the periphery of bowl 100 and pump it through the outlettube 122 to be utilized for other purposes as desired. The disk pickupand pump 120 serves similar purposes as the water pump 22 and water pumpdisk 44b depicted in FIGS. 1 and 2. FIG. 3A depicts an enlargedsectional view taken through the transverse axis of the disk pickupshowing the flow passages. As noted therein, the pumping passages 124diverge to increased cross sectional areas proceeding from the opposingwater inlets 126 to the outlet 122 to convert the velocity pressure tostatic pressure before dumping the water into the outlet 122.

As is apparent from the foregoing description of the liquid/gasseparator embodiment in FIGS. 3 and 3a, and as one skilled in this artwill appreciate, this embodiment provides high liquid flow with low dragon the stationary disk 120. To attain an increased delivery pressure, itwould be necessary to immerse the disk deeper into the water formed atthe periphery of the bowl 102. However, it follows that, drag increasesas a function of the depth the disk is immersed into the water.Obviously, the increased drag has an adverse effect on powerconsumption. For low flow, high delivery pressure separators, disk dragcan account for a significant portion of the total power consumption ofthe separator.

Utilizing the same principles as disclosed herein, FIG. 4 exemplifiesanother embodiment of this invention to alleviate the problem alluded toin the immediately above paragraph. FIG. 4 schematically illustrates thewater/air separator generally depicted by reference numeral 130 forreducing the drag in a high delivery pressure separator and therebyminimizing power consumption and comprises a rotating bowl 132,stationary inlet 134, stationary disk pump 136, motor assembly 138,stationary gas manifold and outlet 140, stationary water tube and outletassembly 142 and gas pressurization tube and inlet 144.

The rotating bowl 132 is a hollow cylindrical closed member with innerannular spaced walls 150 and 152 dividing the bowl into three separatecompartments 132a, 132b and 132c. The separating compartment 132a isisolated from the disk pump compartment 132b similar to the embodimentdepicted in FIGS. 1 and 2. Liquid and gas are admitted internally ofbowl 132 through the stationary inlet where it impinges on thecircumferentially spaced vanes 154 for accelerating the water andflinging it to the periphery of bowl 132 to form a cylindrical mass ofwater and the lighter density gas is forced into the multiple gas outletports 139 circumferentially spaced about the inlet 134. The gas isported to the stationary gas manifold 140 to be used or dumped asdesired.

Passages 151 and 153 formed in the periphery of walls 150 and 152,respectively, allow the water to flow into compartments 132b and 132a.Compartment 132b housing the stationary disk pump 136 is pressurized byadmitting gas pressure through the inlet tube 144 and hence, reduce thedepth of the water cylinder adjacent the periphery of the bowl 132confined within compartment 132b. A suitable seal 160 is attached at thejournal portion 162 for assuring the water is contained in thecompartment 132b. The stationary disk pump 136 is substantially similarto the water pump housing 24 and water pump disk 44b depicted in FIGS. 1and 2 and for the sake of simplicity and convenience are not beingdescribed and are incorporated by reference herein. The disk pump 136serves to pickup the water at the periphery of the bowl 132 and pump itthrough the liquid outlet of assembly 142 for delivery and use asdesired. Circumferentially spaced fins attached to the inner wall ofbowl 132 within the compartment 132b serve to maintain the velocity ofthe water.

As is apparent from the foregoing, the liquid level is allowed toincrease in the separator section of bowl 132. However, since theexternal gas supply pressurizes compartment 132b, this will cause theliquid level to be reduced. Pressure equalizing ports 133 and 135 may beused to equalize the pressure acting on disk pump 136. This permits thedisk pump 136 to behave as if it were submerged to the level in thecompartment 132c, but at a much reduced drag because the liquid level incompartment 132b is suppressed by gas pressure. Obviously, this approachrequires added complexity as compared with the embodiment depicted inFIG. 3, particularly because of the requirement of an external gaspressurization source and a rotating seal 162 needed to isolate andpressurize the pump compartment 132b. However, the efficiency of thisembodiment is very high.

The bowl 132 is rotated by the electric motor assembly 138 (A.C. orD.C.) consisting of the stator 166 and rotor 168 where the rotor isattached to or formed integrally with the end wall 170 of the bowl 132and supported by bearings 172 and 174 located in Journal 162 andadjacent to the liquid and gas inlet 134 at a central opening formed inend wall 174 of the rotating bowl 132. To minimize leakage, deflectors175, 177, and 179 are located where there are potential leakageproblems.

In certain applications it is advantageous to allow the disk pump torotate while it isn't being utilized to perform its pumping function.The disk pump is held stationary while performing its pumping function.The big advantage of this type of system is the savings in powerconsumption. FIG. 5 exemplifies this type system and again employs thebasic principles utilized by the other separator systems disclosedherein. The liquid/gas separator depicted in FIG. 5 is a sectional andschematic view of the separator generally illustrated by referencenumeral 180 as comprising a rotating drum or bowl 182, the disk pump184, clutch 186, probe 188, and electric motor 190.

The separator 180 includes a centrally disposed cylindrically shapedinner housing 192 supporting the probe 188 and bearings 189 forrotatably supporting the disk pump 184 and the integral liquid outletport 194 for pumping the separated liquid as will be describedimmediately below. The bearings 184 include axial vent holes to vent theair and liquid during start up.

Similar to the configuration depicted in FIG. 4, separator 180 includesmultiple air outlet ports 196 for venting the separated gases. Similarto the configurations of the other separators disclosed herein, bowl 182is continuously rotated by motor 190. The air/liquid mixture admittedinternally in bowl 182 encounters the separator vanes 200 thataccelerate the mixture and separate the liquid from the gas. The heavierliquid is flung to the periphery of the bowl 182 and forms acylindrically shaped mass. Similar to the disk pump 44b depicted in FIG.1, the disk pump 184 extends so that the inlet is immersed in the water.When the probe is in the position shown in FIG. 5, i.e. whiledisengaged, the disk is freewheeling by virtue of being rotated by therotating water mass. Suitable means are utilized to actuate the clutchwhen water is to be removed from the separator. For this purpose asuitable electronic controller depicted by box 202, senses the waterlevel by sensor 204, which causes the electronic controller to convertthis signal to an output signal to activate the spring loaded probe 188.The probe 188 is held out of engagement of the water outlet port 184 byspring 206 urging the probe toward the left as viewed in the FIG. 5.When the clutch is activated, the probe is urged toward the right sothat the valve end 208 seats into port 194 and the seal 210 engages thewall of port 194 to stop the rotation of disk pump 184. When in thestationary position, disk pump 184 pumps the water out of the bowl 182via an internal passageway in probe 208 which is fluidly connected toconduit 212. A suitable one way check valve allows the water to flow outof the system upon reaching a predetermined pressure. An on/offelectrical switch initially activates the electronic controller 202 andthe electric motor 190. The primary purpose for the clutch and probe isto allow the disk to stop and allow it to be purged of all the air priorto when it is activated to pump the liquid.

It is apparent from the foregoing that the freewheeling disk pump 184consumes almost no power until it is stopped by the mechanical clutch186 actuated by the liquid level sensor 204. Once the disk pump 184 isstopped, the disk pump 184 causes the liquid to be pumped out of therotating bowl 182 at a high flow rate. At high flow, the disk providesgood pumping efficiency and high outlet pressure. As the liquid level inthe bowl is reduced, the level sensor 204 release clutch 186 allowingthe disk pump to freewheel again. The rotating bowl 182 acts as anaccumulator again until the liquid level rises sufficiently to actuateclutch 186 for starting the cycle over again.

The liquid/gas separator exemplified in FIG. 6, again using the sameprinciples as utilized by the other separators depicted herein, isparticularly useful in a microgravity environment where it is necessaryto separate the liquid from gas in a rotating bowl at very lowrotational speeds. As one skilled in this art will appreciate, it is thepumping pressure requirement that demands high rotational speeds. In agravity field, higher rotational speeds are required to keep thecylindrical mass of liquid from collapsing. Since power consumption isproportional to the cube of rotational speed, it is highly desirable torun at the minimum rotational speed consistent with good separation. Theseparator depicted in FIG. 6, which is particularly efficacious foroperation with these parameters includes the rotating bowl 230 suitablyrotated by a motor (not shown) connected to shaft 232. In thisconfiguration the disk pump 231 is fixed internally of bowl 230 andconsists of two parallel disks 234 and 236.

The liquid/air mixture is admitted internally of bowl 230 through inlet240 where it encounters the separator impellers 242 for accelerating themixture and causing it to separate, flinging the heavier liquid to theperiphery of bowl 230. the air is collected by the multiple outlet ports244 (similar to gas outlet ports 139 depicted in FIG. 4) and vented. Asuitable positive displacement pump 250 disposed in conduit 248 isfluidly connected to disk pump 231 via outlet port 252 and thestationary outlet tube 254 disposed along the axial center line X ofrotating bowl 230. A suitable pressure sensor 256 and electroniccontroller 258 sense the static pressure of the liquid in the disk pump231 and controls the speed of the positive displacement pump 250 tomaintain the liquid level just covering the periphery of the disk pump231 so as to ensure gas-free delivery of the liquid with minimal drag.Pumping of the liquid out of the rotating bowl 230 is intermittent byvirtue of the judicious actuation of the positive displacement pump 250.The one-way check valve 260 is disposed at the outlet of positivedisplacement pump 250 to permit the flow of liquid out of the systemupon reaching a predetermined pressure.

Obviously, the conductivity sensor disclosed in the embodiment depictedin FIGS. 1 and 2 could be substituted for the pressure sensor utilizedin the separator depicted in FIG. 6. As with the pressure sensor, theconductivity sensor would activate the positive displacement pump whenthe level of the water reaches a predetermined depth.

What has been shown by the embodiment depicted in FIG. 6 is a separatorthat not only requires a low speed for the rotating bowl which accountsfor reduction in power consumption, the use of a positive displacementpump instead of the customary centrifugal pump utilized in spaceapplications contributes to a more efficient separation system. This isparticularly true because of the low liquid flow rates that aregenerally encountered in space applications. Another advantage for theseparator depicted in FIG. 6 is that the liquid quantity can be simplyand accurately determined by counting the strokes or revolutions of thepositive displacement pump. This would be particularly useful inspacecraft urine separators where data on urine collected would behelpful in the designing of life support systems for future missions orfor human metabolic studies.

Although this invention has been shown and described with respect todetailed embodiments thereof, it will be appreciated and understood bythose skilled in the art that various changes in form and detail thereofmay be made without departing from the spirit and scope of the claimedinvention.

I claim:
 1. A fluid/liquid separator for separating the mixture of thefluid and liquid into separate components of fluid and liquid comprisinga rotating drum rotating about a central axis, a first pumping meansattached to said rotating drum including a rotating housing extendingradially inward toward said central axis for defining a firstcompartment and a second compartment disposed in axial alignment withsaid first compartment, means for imparting rotary motion to saidrotating drum so that the angular velocity of said rotating drum issufficiently high to separate the fluid from the liquid admitted intosaid rotating drum through an inlet in said first compartment, saidfirst pumping means having an inlet for admitting said separated fluidinto said first pumping means for pumping said separated fluid, fluidpassage means interconnecting said first pumping means and an outlet insaid second compartment, a second pumping means including a secondrotating housing attached to said rotating drum and being in axialalignment with said first pumping means and being disposed in saidsecond compartment and being in fluid flow relationship with saidseparated liquid, liquid passage means interconnecting said secondpumping means and an outlet formed in said second compartment and anenergy recovery means disposed between said first pumping means and saidsecond pumping means for reducing the power demand on the means forimparting rotary motion.
 2. A fluid/liquid separator for separating themixture of the fluid and liquid into separate components of fluid andliquid as claimed in claim 1 wherein said fluid is oil and said liquidis water.
 3. A fluid/liquid separator for separating the mixture of thefluid and liquid into separate components of fluid and liquid as claimedin claim 2 including circumferentially spaced paddles in said firstcompartment for accelerating the angular velocity of the oil and watermixture entering said rotating drum.
 4. A fluid/liquid separator forseparating the mixture of the fluid and liquid into separate componentsof fluid and liquid as claimed in claim 3 including coalescer meansdisposed in said first compartment.
 5. A fluid/liquid separator forseparating the mixture of the fluid and liquid into separate componentsof fluid and liquid as claimed in claim 4 wherein said coalescer meansis a porous filter mesh.
 6. A fluid/liquid separator for separating themixture of the fluid and liquid into separate components of fluid andliquid as claimed in claim 5 wherein said paddles are embedded in saidporous filter mesh.
 7. A fluid/liquid separator for separating themixture of the fluid and liquid into separate components of fluid andliquid as claimed in claim 5 wherein said inlet in said firstcompartment is stationary relative to said rotating drum.
 8. Afluid/liquid separator for separating the mixture of the fluid andliquid into separate components of fluid and liquid as claimed in claim7 wherein said first pumping means includes an oil pump diskconcentrically mounted in said rotating housing of said first pumpingmeans comprising a plurality of circumferentially spaced vanes in fluidcommunication with said oil solely when the oil level in said firstcompartment reaches a predetermined value in said rotating drum, saidrotating housing of said first pumping means having an inlet.
 9. Afluid/liquid separator for separating the mixture of the fluid andliquid into separate components of fluid and liquid as claimed in claim8 wherein said second pumping means includes a stationary disk includinga plurality of radial vanes in fluid communication with the separatedwater solely when the separated water level reaches a predeterminedlevel in said rotating drum.
 10. A fluid/liquid separator for separatingthe mixture of the fluid and liquid into separate components of fluidand liquid as claimed in claim 9 wherein said water is rotating andforming vortices and wherein the energy recovery means comprises arotating disk including an inlet in proximity to said central axis andan outlet adjacent the rotating housing of said second pumping means toflow the water in a radial direction so as to remove the vortices of thewater prior to entering said second pumping means.
 11. A fluid/liquidseparator for separating the mixture of the fluid and liquid intoseparate components of fluid and liquid as claimed in claim 10 whereinair is entrained in said mixture of fluid and liquid and wherein thediameter of the inlet to the rotating housing of said first pumpingmeans relative the diameter of the said inlet in said first compartmentis such that air trapped in the fluid/oil mixture upstream of said firstpumping means will escape from said rotating drum through an openingformed adjacent to said inlet.
 12. A fluid/liquid separator forseparating the mixture of the fluid and liquid into separate componentsof fluid and liquid as claimed in claim 11 including means forcontrolling admittance of oil into said inlet of said fluid passagemeans for controlling the flow of oil from said outlet of said fluidpassage means.
 13. A fluid/liquid separator for separating the mixtureof the fluid and liquid into separate components of fluid and liquid asclaimed in claim 12 wherein said controlling means includes aconductivity sensor immersed in the separated water for sensing theconductivity of said water for producing an output signal as a functionof the change in conductivity and a fluid regulator in response to saidoutput signal for regulating flow of water from said outlet of saidliquid passage means.
 14. Apparatus for separating fluid and liquid froma fluid/liquid mixture comprising a rotating drum rotatably supportedabout a central axis, said rotating drum having a first compartment withan inlet for admitting said liquid/fluid mixture in said rotating drumand a second compartment in fluid flow relationship and axially disposedrelative to said first compartment, means for imparting rotary motion tosaid rotating drum for centrifuging said fluid/liquid mixture forseparating the liquid and the fluid into separate fluid and liquidcomponents in said first compartment, pumping means in said secondcompartment for pumping said liquid component, outlet means connected tosaid pumping means for independently discharging said liquid componentfrom said rotating drum, an additional outlet means fluidly connected tosaid rotating drum for discharging said fluid component, and furthercomprising an energy recovery means disposed in said second compartmentfor recovering centrifugal energy from said liquid component tofacilitate rotating the drum.
 15. Apparatus for separating fluid andliquid from a fluid/liquid mixture as claimed in claim 14 wherein saidfluid is oil and said liquid is water.
 16. Apparatus for separatingfluid and liquid from a fluid/liquid mixture as claimed in claim 14wherein said fluid is air and said liquid is water.
 17. Apparatus forseparating oil and water from an oil/water mixture comprising a rotatingdrum rotatably supported about a central axis, said rotating drum havinga first compartment with an inlet for admitting said oil/water mixturein said rotating drum and a second compartment in fluid flowrelationship and axially disposed relative to said first compartment,means for imparting rotary motion to said rotating drum for centrifugingsaid oil/water mixture for separating the water and the oil intoseparate oil and water components in said first compartment, pumpingmeans in said second compartment for pumping said oil and watercomponents, and respective outlet means connected to said pumping meansfor independently discharging said oil and water components from saidrotating drum, wherein said pumping means includes a first pump forpumping the water component and a second pump for pumping the oilcomponent, and including an energy recovery means disposed in saidsecond compartment between said first pump and said second pump, saidenergy recovery means being in fluid flow relationship with respect tosaid first pump.
 18. Apparatus for separating fluid and liquid from afluid/liquid mixture comprising a rotating drum rotatably supportedabout a central axis, said rotating drum having a first compartment withan inlet for admitting said fluid/liquid mixture in said rotating drumand a second compartment in fluid flow relationship and axially disposedrelative to said first compartment, means for imparting rotary motion tosaid rotating drum for centrifuging said fluid/liquid mixture forseparating the liquid and the fluid into separate fluid and liquidcomponents in said first compartment, pumping means in said secondcompartment for pumping said fluid and liquid components, and respectiveoutlet means connected to said pumping means for independentlydischarging said liquid component and said fluid component from saidrotating drum and having pressurizing means for pressurizing said secondcompartment to reduce the level of immersion of said pumping means insaid separated liquid component.
 19. Apparatus for separating fluid andliquid from a fluid/liquid mixture as claimed in claim 18 includingmeans responsive to the pressure in said second compartment forgenerating a pressure signal, control means responsive to said pressuresignal for regulating the flow through said outlet means.
 20. Apparatusfor separating fluid and liquid components from a fluid/liquid mixturecomprising a rotating drum rotatably supported about a central axis,said rotating drum having a first compartment with an inlet foradmitting said fluid/liquid mixture in said rotating drum, and a secondcompartment in fluid flow relationship and axially disposed relative tosaid first compartment, means for imparting rotary motion to saidrotating drum for centrifuging said fluid/liquid mixture for separatingthe liquid and the fluid into separate components in said firstcompartment, pumping means in said second compartment for pumping saidliquid component, and respective outlet means connected to said pumpingmeans for independently discharging said liquid component and said fluidcomponent from said rotating drum, wherein valve means are fluidlyconnected to said outlet means for said liquid component for opening andclosing said outlet means for said liquid component, said pumping meansis rotating when said outlet means for said liquid component is closed,and means including clutch means to hold said pumping means in astationary position and to open said outlet means for said liquidcomponent.
 21. Apparatus for separating fluid and liquid from afluid/liquid mixture as claimed in claim 20 including liquid levelsensing means disposed in said first compartment for sensing the levelof the separated liquid for generating a water level signal and controlmeans responsive to said water level signal for controlling said clutchmeans.